<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">

    <title>猜数字游戏</title>

    <style>
      html {
        font-family: sans-serif;
      }

      body {
        width: 50%;
        max-width: 800px;
        min-width: 480px;
        margin: 0 auto;
      }

      .lastResult {
        color: white;
        padding: 3px;
      }
    </style>
  </head>

  <body>
    <h1>猜数字游戏</h1>

    <p>我刚才随机选定了一个100以内的自然数。看你能否在 10 次以内猜中它。每次我都会告诉你所猜的结果是高了还是低了。</p>

    <div class="form">
      <label for="guessField">请猜数: </label>
      <input type="text" id="guessField" class="guessField">
      <input type="submit" value="确定" class="guessSubmit">
    </div>

    <div class="resultParas">
      <p class="guesses"></p>
      <p class="lastResult"></p>
      <p class="lowOrHi"></p>
    </div>

    <script>

        // 开始编写 JavaScript 代码
        let randomNumber = Math.floor(Math.random() * 100) + 1; //均衡获取0到100的随机整数 

        const guesses = document.querySelector('.guesses');
        const lastResult = document.querySelector('.lastResult');
        const lowOrHi = document.querySelector('.lowOrHi');

        const guessSubmit = document.querySelector('.guessSubmit');
        const guessField = document.querySelector('.guessField');

        let guessCount = 1; //记录玩家当前的轮数
        let resetButton;

        function checkGuess(){
            let userGuess = Number(guessField.value);
            if(guessCount === 1){
                guesses.textContent = '上次猜的数是: ';
            }
            guesses.textContent += userGuess + ' ';

            if (userGuess === randomNumber) {
                lastResult.textContent = '恭喜你！猜对了';
                lastResult.style.backgroundColor = 'green';
                lowOrHi.textContent = '';
                setGameOver();
            } else if (guessCount === 10) {
                lastResult.textContent = '!!!GAME OVER!!!';
                setGameOver();
            } else {
                lastResult.textContent = '你猜错了！';
                lastResult.style.backgroundColor = 'red';
                if(userGuess < randomNumber) {
                lowOrHi.textContent = '你猜低了！';
                } else if(userGuess > randomNumber) {
                lowOrHi.textContent = '你猜高了';
                }
            }

            guessCount++;
            guessField.value = '';
            guessField.focus();
        }

        guessSubmit.addEventListener('click', checkGuess);

        function setGameOver() {
            guessField.disabled = true;
            guessSubmit.disabled = true;
            resetButton = document.createElement('button');
            resetButton.textContent = '开始新游戏';
            document.body.appendChild(resetButton);
            resetButton.addEventListener('click', resetGame);
        }

        function resetGame() {
            guessCount = 1;

            const resetParas = document.querySelectorAll('.resultParas p');
            for (let i = 0 ; i < resetParas.length; i++) {
                resetParas[i].textContent = '';
            }

            resetButton.parentNode.removeChild(resetButton);

            guessField.disabled = false;
            guessSubmit.disabled = false;
            guessField.value = '';
            guessField.focus();

            lastResult.style.backgroundColor = 'white';

            randomNumber = Math.floor(Math.random() * 100) + 1;
        }

    </script>
  </body>
</html>